Wireless networks are telecommunications networks that use radio waves to carry information from one node in the network to one or more receiving nodes in the network. Wired communication can also be used in portions of a wireless network, such as in the core network. Cellular telephony is characterized by the use of radio cells that provide radio coverage for a geographic area, with multiple cells arranged to provide contiguous radio coverage over a larger area. Mobile devices use radio waves to communicate with the cellular radio cells, and the mobile devices can move from one cellular radio cell to another.
Mobile data service providers are facing shortage of IPv4 IP address. Network Address Translation (NAT) addresses this concern by sharing an IP address among many mobile subscribers instead of assigning separate IP address for each Mobile Subscriber (MS). NAT works by assigning private (not globally unique) IPv4 address to each MS for use internally and translating the private IP address and source port information to a globally unique IP address. This involves assigning a different port for each data connection from mobile device. The NAT mapping is computed when the first data packet arrives at the NAT for each new data connection. NAT does an IP address and port translation on all subsequent data packets on the same data connection. NAT also does a reverse translation of packets arriving from the public network that are destined to the MS. With address and port translation, this process is also sometimes called Network Address and Port Translation (NAPT). The mapping information from NAT can be communicated to other systems for real time usage and for future usage as well. However, the amount of mapping information generated for a given MS can be very large, running into thousands of mappings, which needs to be communicated, processed, and stored. This process can create a bottleneck in scalable high performance systems.